package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    /**
     * 关注 or 取关
     * @param followUserId
     * @param isFlow
     * @return
     */
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;
    @Override
    public Result follow(Long followUserId, Boolean isFlow) {
        //1.获取当前登录 id
        Long userId = UserHolder.getUser().getId();
        String key= "follow:"+userId;
        //1.判断是否关注还是取关
        if (isFlow){
            //2.关注，新增数据
            Follow follow = new Follow();
          follow.setFollowUserId(followUserId);
          follow.setUserId(userId);
            boolean isSuccess = save(follow);

            if (isSuccess){
                //数据库保存成功，保存到redis里面
           stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else{
            //3.删除 delet from tb_follow where user_id =? and follow_user_id=?
            boolean isSuccess = remove(new QueryWrapper<Follow>().eq("user_id", userId).eq("follow_user_id", followUserId));
            if (isSuccess){
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }



        }

        return Result.ok();
    }

    /**
     * 判断是否关注
     * @param followUserId
     * @return
     */
    @Override
    public Result isFollow(Long followUserId) {
        //获取当前登录用户
        Long userId = UserHolder.getUser().getId();
        //查询用户是否关注
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count>0);
    }

    /**
     * 共同关注
     * @param id
     * @return
     */
    @Override
    public Result followCommons(Long id) {
        //1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key1= "follow:"+userId;
        String key2="follow:"+id;
        //求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);
        if (intersect==null||intersect.isEmpty()){

            return Result.ok(Collections.emptyList());
        }
        //解析id集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //根据ids查询 user信息
        List<UserDTO> users = userService.listByIds(ids).stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());

        return Result.ok(users);
    }
}
